Ice cream is a frozen dessert typically made from milk or cream that has been flavoured with a sweetener, either sugar or an alternative, and a spice, such as cocoa or vanilla, or with fruit, such as strawberries or peaches.
The mixture is cooled below the freezing point of water and stirred to incorporate air spaces and prevent detectable ice crystals from forming. It can also be made by whiskin a flavoured cream base and liquid nitrogen together.
The result is a smooth, semi-solid foam that is solid at very low temperatures (below 2 °C or 35 °F). It becomes more malleable as its temperature increases.
Learn more on Wikipedia